Five or so years ago, Vivian Johnson, a retired professor of education at Boston University, was poking through records in the Massachusetts Historical Society — she loves to do research — looking for information about how African-Americans educated their children in the 17th century, when she came across something that would occupy her for the next five or so years.

It was a woman’s name, Zipporah Potter, along with one bit of information that Johnson found impossible: that she was a 17th century African-American woman who owned property in the North End. Both of these facts put her way, way ahead of her time and make her the first African- American landowner in Boston, male or female.

“What makes this so exciting is that during this period that we’re talking about, from 1641, Africans were enslaved in Boston, so not only was she unusual because she was free, but the likelihood of anyone having purchased land was not very good, especially for a woman,” said Johnson.

Johnson found the deed to the house, which Potter purchased in 1670, and a 1676 map that depicted it just next to where a mill pond emptied into a creek that carried it to the bay. The pond and the creek are long gone, as is the colossal highway that kept the property in shadows for decades. The spot is now a nice stretch of mowed grass on the Rose Kennedy Greenway, just off where Hanover Street crosses. A historical plaque will be unveiled at the site Tuesday, with a dedication by Governor Deval Patrick.

Zipporah had six surnames, at a time when these were rare for people of African descent. When she married and became Zipporah Potter Atkins, the ceremony was officiated by Cotton Mather, the great Protestant minister of his time.

Records indicate she inherited some money when her father, a slave, died, and that is what she used to buy the house and property. But how she remained free and how she used that inheritance to acquire land when blacks and women did not, remains an intriguing mystery.

“This was tricky beyond what anybody can fully comprehend,” said Beverly Morgan-Welch, executive director of the Museum of African American History in Boston, which worked with Johnson. “It looks like she’s the only black person here who hasn’t been enslaved, and this is a time when white women didn’t own property. How in the world does she pull this off? Not only does she buy property, but she holds onto it for nearly 30 years, even after she’s married.”

1670

Records show that Potter, who bought the property for 46 pounds, sold a chunk of it for 100 pounds in 1693, and the rest of it in 1699 for 25 pounds. And after poring over deeds from that time, Johnson could find no older records of property ownership for African-Americans in Boston.

The discovery of Zipporah Potter and her land, Morgan-Welch said, is more than an interesting fact. “This is a piece of property, and place means everything,” she said. “She was amazing, but it will lead us to other people. Who was she interacting with? Boston was a place where people were struggling to figure out liberties and ideas, and some of those ideas made it into the Constitution, and along comes Zipporah Potter Atkins.”

The historic marker is the 14th placed by the Heritage Guild, which Johnson works closely with, and represents a collaboration with the Museum of African American History and the Rose Kennedy Greenway Conservancy, which moved the project to reality. The ceremony will begin at 1:15 p.m. Tuesday. Patrick issued a statement saying he is honored to “commemorate her extraordinary life and accomplishments that contributed toward transforming our nation.”

On Thursday at 6 p.m., Johnson will give a lecture at the museum, on Beacon Hill, exploring the question of how this particular woman was able to be more than a century ahead of her time.

“She doesn’t just pop out of nowhere, buy a house, and sustain it when this sort of thing is not done by women, period,” Morgan-Welch said. “And clearly, she knows Cotton Mather. He’s no slouch. There’s still a lot we need to know about her, but what we do know is wonderfully exciting.”